Sensor film for endoscopic instruments

ABSTRACT

A method for sensing at least one property with an instrument, wherein the instrument comprises an elongate shaft body; the method comprising the steps of: securing a sensor film conformally to the elongate shaft body, the sensor film comprising: at least one substrate core having a first surface and a second surface; at least one sensing element; a first conductive layer residing on the first surface, the first conductive layer having first solder mask coated thereon, and wherein the first conductive layer is grounded; a second conductive layer residing on the second surface, the second conductive layer having a second solder mask coated thereon, and coupled to the at least one sensing element; causing the at least one sensing element to measure at least one property and output a sensed signal and to convey the sensed signal via the second conductive layer to an electronics module.

This application is a divisional of U.S. Non-Provisional applicationSer. No. 16/072,834 filed on Jul. 25, 2018, which was a National StageApplication filed under 35 U.S.C. 371 of International Application No.PCT/CA2017/050103, filed 27 Jan. 2017, which claims the benefit ofpriority to U.S. Provisional Application Ser. 62/289,120, filed on Jan.29, 2016, the contents of which are hereby incorporated by reference.

FIELD

The present disclosure relates to endoscopic surgery and moreparticularly to endoscopic instruments associated with one or moresensors.

BACKGROUND

Traditional open surgery uses surgical tools and techniques that put thesurgeon in direct contact with tissue at the surgical site. Accordingly,surgeons are able to assess the amount of force they are applying to theoften delicate tissue when operating with help of surgical tools.Generally, the application of excessive forces on the tissue may lead todamage, such as bruising, tearing, or worse. While traditional opensurgery gives surgeons some control of the force on the tools, this typeof surgery requires a large amount of dissection to reach internalsurgical sites. In order to significantly reduce the amount ofdissection required to access the surgical site, traditional surgery isbeing replaced with endoscopic surgery.

Endoscopic surgery is a method of surgery in which elongated tools areinserted through small incisions made on the body. These endoscopictools, or instruments, consist of a proximal handle, an elongated memberextending from the handle, and a distal end effector. End effectors maybe, but are not limited to, graspers, snares, scissors, needles, orretractors. Endoscopic instruments are inserted into the body throughtrocars which provide a conduit for the endoscopic instruments. Trocarsconsist of a sharp, removable distal tip, a hollow medical tube, and aproximal bulb. Generally, the trocar is inserted into the body through asmall incision dimensioned to fit the sharp, removable tip, and thetrocar is advanced into the body until the tip reaches the surgicalsite. Trocars are manufactured in standard sizes for trocar andendoscopic instrument interoperability. In addition to creating thechannels into the body and protecting the surrounding tissue from damagefrom tool friction, the trocars can also act as a port for injecting agas, such as nitrogen, oxygen, or air into the cavity to expand thecavity and create a larger working area for the endoscopic instruments.The gap between the endoscopic instrument and trocar is minimized toprevent the gas from escaping.

While endoscopic surgery significantly reduces the amount of dissectionrequired to reach internal surgical sites, it also introduces a host ofproblems for the surgeon to contend with. Trocars create a fulcrumeffect which changes the mechanical advantage of an endoscopicinstrument as it is translated in or out of the trocar. The instrumentsare often at much higher or lower mechanical advantage due to length ofthe instruments. Finally, trocars create friction that varies withlubrication and loading perpendicular to the medical tube. All of thesemechanics make it significantly more difficult for surgeons toaccurately assess the amount of force they apply to the tissue. Giventhat most tissue is relatively delicate, excessive application of forcecan bruise, tear, and kill tissue leading to surgical complications,poorer surgical outcomes, and/or patient discomfort. Additionally, tyingsuture knots requires a precise application of force, as tying the knottoo tightly can cause the tissue being joined to die, while tying toolightly can lead to leakage or poor healing.

Various approaches have been proposed in an attempt to measure forcesapplied to the tissue when using endoscopic instruments. For example, inone approach distal sensors are coupled to the exterior of theinstrument using wiring inserted in grooves that are machined into theshaft of the instrument. However, this method requires the instrument tobe modified to accommodate the sensors and create the grooves in theshaft of the instrument.

In yet another approach, a sheath with sensors and wiring embeddedtherein is placed over the instrument. However, these sheaths are toothick to fit between an existing endoscopic instrument and its intendedsize of trocar, therefore either the next larger size of trocar must beused, or the trocar or the instrument must be redesigned to accommodatethe increased bulk. Additionally, the sheath is an extra item that mustbe sterilized and, since the sheath is not in perfect contact with theshaft of the instrument, the sensor readings may not be recorded, andtherefore some time periods may have missing sensor readings. Thisinconsistency in the sensor readings renders this approach unreliableand unsuitable.

In yet another approach, distal sensors are coupled with wiring on theinterior of the instrument. However, this approach requires the sensorsto be built into the instrument during manufacturing or requires theinstrument to be designed to be disassembled.

It is an object of the present disclosure to mitigate or obviate atleast one of the above-mentioned disadvantages.

SUMMARY

In one of its aspects, there is provided an endoscopic instrument foruse with a trocar, said endoscopic instrument comprising:

-   -   an elongate shaft body having a proximal end and a distal end;    -   an end effector assembly at said distal end operable by        manipulation of actuator mechanism at said proximal end;    -   a substrate core having a first surface and a second surface;        and wherein said substrate is conformally attached to said        elongated shaft body    -   at least one sensing element on said elongate shaft body, said        at least one sensing element located adjacent to said distal        end;    -   an electronics module for receiving sensed signals from said at        least one sensing element, said electronics module located        adjacent to said proximal end;    -   a first conductive layer residing on said first surface, said        first conductive layer having a first solder mask coated        thereon; and    -   a second conductive layer residing on said second surface,        second conductive layer having a second solder mask coated        thereon, and wherein said second conductive layer coupled to        said at least one sensing element relays said sensed signals        from said at least one sensing element to said electronics        module and said a first conductive layer is grounded.

In another of its aspects, there is provided an endoscopic instrumentfor use with a trocar, said endoscopic instrument comprising:

-   -   an elongate shaft body having a proximal end and a distal end;    -   an end effector assembly at said distal end operable by        manipulation of actuator mechanism at said proximal end;    -   a substrate core having a first surface and a second surface;        and wherein said substrate is conformally attached to said        elongated shaft body;    -   at least one sensing element on said elongate shaft body, said        at least one sensing element located adjacent to said distal        end;    -   an electronics module for receiving sensed signals from said at        least one sensing element, said electronics module located        adjacent to said proximal end;    -   a first conductive layer residing on said first surface, said        first conductive layer having a low friction, non-conductive        layer thereon;    -   a second conductive layer residing on said second surface,        second conductive layer having a solder mask coated thereon, and        wherein said second conductive layer coupled to said at least        one sensing element relays said sensed signals from said at        least one sensing element to said electronics module and said a        first conductive layer is grounded; and    -   said low friction, non-conductive layer is adhered to first        conductive layer via an adhesive to surround edges of said        substrate core, second conductive layer and solder mask.

In another of its aspects, there is provided an endoscopic instrumentfor use with a trocar, said endoscopic instrument comprising:

-   -   an elongate shaft body having a proximal end and a distal end;    -   an end effector assembly at said distal end operable by        manipulation of actuator mechanism at said proximal end;    -   at least one sensing element on said elongate shaft body, said        at least one sensing element located adjacent to said distal        end;    -   an electronics module for receiving sensed signals from said at        least one sensing element, said electronics module located        adjacent to said proximal end;    -   an upper substrate core;    -   a lower substrate core; and wherein said upper substrate core        and said lower substrate core are conformally attached to said        elongated shaft body;    -   an intermediate conductive layer between said upper substrate        core and said lower substrate core;    -   a first conductive layer residing on said upper substrate core,        and said first conductive layer having a first solder mask        coated thereon;    -   a second conductive layer residing below said second conductive        layer, and having a second solder mask coated thereon; and    -   wherein said intermediate conductive layer relays said sensed        signals, and said first conductive layer and second conductive        layer are grounded.

In another of its aspects, there is provided an endoscopic instrumentfor use with a trocar, said endoscopic instrument comprising:

-   -   an elongate shaft body having a proximal end and a distal end;    -   an end effector assembly at said distal end operable by        manipulation of actuator mechanism at said proximal end;    -   a substrate core having a first surface and a second surface;        and wherein said substrate is conformally attached to said        elongated shaft body;    -   at least one sensing element on said elongate shaft body, said        at least one sensing element located adjacent to said distal        end;    -   an electronics module for receiving sensed signals from said at        least one sensing element, said electronics module located        adjacent to said proximal end;    -   a sheet of grounded ferromagnetic metal residing on said first        surface, said a sheet of grounded ferromagnetic metal; and    -   a conductive layer residing on said second surface, second        conductive layer having a solder mask coated thereon, and        wherein said second conductive layer is coupled to said at least        one sensing element to relay said sensed signals from said at        least one sensing element to said electronics module.

In another of its aspects, there is provided an endoscopic instrumentfor use with a trocar, said endoscopic instrument comprising:

-   -   an elongate shaft body having a proximal end and a distal end;    -   an end effector assembly at said distal end operable by        manipulation of actuator mechanism at said proximal end;    -   at least one sensing element on said elongate shaft body, said        at least one sensing element located adjacent to said distal        end;    -   an electronics module for receiving sensed signals from said at        least one sensing element, said electronics module located        adjacent to said proximal end;    -   an upper substrate core;    -   a lower substrate core; and wherein said upper substrate core        and said lower substrate core are conformally attached to said        elongated shaft body;    -   an intermediate conductive layer between said upper substrate        core and said lower substrate core;    -   a sheet of grounded ferromagnetic metal residing on said upper        substrate core, and said sheet of grounded ferromagnetic metal        first conductive layer having a low friction, non-conductive        layer;    -   a second conductive layer residing below said second conductive        layer, and having a second solder mask coated thereon; and    -   wherein said low friction, non-conductive layer is adhered to        said sheet of grounded ferromagnetic metal via an adhesive and        around edges of said upper substrate core, a lower substrate        core, intermediate conductive layer, second conductive layer and        second solder mask; and    -   wherein said intermediate conductive layer relays said sensed        signals, and said sheet of grounded ferromagnetic metal and        second conductive layer are grounded.

In another of its aspects, there is provided a method for sensing atleast one property associated with an end effector of an endoscopicinstrument during a surgical procedure, wherein said endoscopicinstrument is used via a trocar, said endoscopic instrument comprisingan elongate shaft body having a proximal end and a distal end, and anend effector assembly at said distal end operable by manipulation ofactuator mechanism at said proximal end; said method comprising thesteps of:

-   -   securing a sensor film conformally on said elongate shaft body,        said sensor film comprising:    -   a substrate core having a first surface and a second surface;        and wherein substrate core is conformally attached to said        elongated shaft body;    -   at least one sensing element located adjacent to said distal        end;    -   a first conductive layer residing on said first surface, said        first conductive layer having first solder mask coated thereon,        and wherein said first conductive layer is grounded;    -   a second conductive layer residing on said second surface,        second conductive layer having a second solder mask coated        thereon, and coupled to said at least one sensing element;    -   causing said at least one sensing element to measure at least        one property and output a sensed signal and to convey said        sensed signal via said second conductive layer to an electronics        module;    -   at said an electronics module, receiving said sensed signal and        processing said sensed signal to determine said property.

In another of its aspects, there is provided a sensor film comprising:

-   -   a substrate core having a first surface and a second surface;    -   at least one sensing element for sensing at least one property;    -   a first conductive layer residing on said first surface, said        first conductive layer having first solder mask coated thereon,        and wherein said first conductive layer is grounded; and    -   a second conductive layer residing on said second surface,        second conductive layer having a second solder mask coated        thereon, and coupled to said at least one sensing element.

Advantageously, there is provided a sensor film that can be readilyassociated with a standard surgical instrument, such as an endoscopicinstrument, in order to add sensing capability or functionality to thesurgical instrument. The sensor film comprises a thin conformalsubstrate, which allows an existing endoscopic instrument to communicatewith sensors at the distal tip of the instrument without modification.The sensor film is dimensioned such that the instrument with the sensorfilm can be used with the existing trocar intended for the instrument,and without requiring that the sensors and wiring be built into theinstrument during manufacture or require the ability to disassemble thetool.

The signals detected by the sensor film are processed and interpreted,and relayed to the surgeon to provide real-time feedback, and alertsbased on predetermined thresholds. More specifically, the standardsurgical instrument is retrofitted with the sensor film, therebyforegoing the acquisition costs and maintenance costs associated withspecialized sensing surgical instruments. In addition, the sensor filmsare interchangeable, such that multiple sensors may be associated withany particular instrument, which adds versatility to any instrument.Accordingly, should a sensor film, or sensors, fail then only the sensorfilm will require replacement, and not the entire instrument, as iscommon with some of specialized prior art sensing surgical instruments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an endoscopic instrument associated with a sensor film;

FIGS. 2 a to 2 e show various flexible proximal shaft configurations;

FIGS. 3 a to 3 e show various substrate laminations;

FIG. 4 shows a cross-section of a distal section of the endoscopicinstrument with strain gauges;

FIGS. 5 a to 5 e show different distal sensor types and configurations;

FIGS. 6 a to 6 c show various strain gauge configurations;

FIG. 7 shows positioning of additional sensing elements on theendoscopic instrument;

FIG. 8 a shows a feedback system, in one exemplary implementation; and

FIG. 8 b shows a feedback system, in another exemplary implementation.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings.Wherever possible, the same reference numbers are used in the drawingsand the following description to refer to the same or similar elements.While embodiments of the disclosure may be described, modifications,adaptations, and other implementations are possible. For example,substitutions, additions, or modifications may be made to the elementsillustrated in the drawings, and the methods described herein may bemodified by substituting, reordering, or adding stages to the disclosedmethods. Accordingly, the following detailed description does not limitthe disclosure. Instead, the proper scope of the disclosure is definedby the appended claims.

Moreover, it should be appreciated that the particular implementationsshown and described herein are illustrative of the invention and are notintended to otherwise limit the scope of the present invention in anyway. Indeed, for the sake of brevity, certain sub-components of theindividual operating components, and other functional aspects of thesystems may not be described in detail herein. Furthermore, theconnecting lines shown in the various figures contained herein areintended to represent exemplary functional relationships and/or physicalcouplings between the various elements. It should be noted that manyalternative or additional functional relationships or physicalconnections may be present in a practical system.

FIG. 1 shows an exemplary surgical instrument 10, such as an endoscopicinstrument for use in minimally invasive surgery, with exemplary sensorfilm 12. As can be seen, surgical instrument 10 comprises elongate shaftbody 14 with proximal end 16 and distal end 18, and end effectorassembly 20 at distal end 18 operable by manipulation of actuatormechanism 22 at proximal end 18. Accordingly, actuator mechanism 22 andend effector assembly 20 are interconnected via a push rod or wire (notshown) within elongate shaft body 14. Sensor film 12 comprises substrate23 with one or more sensing elements 24 coupled to a communicationmedium 26 extending therefrom for relaying sensed signals to electronicsmodule 28 at proximal end 16 for processing. Generally, sensor film 12is placed onto elongate shaft body 14, and secured thereto by attachmentmeans, such that sensing elements 24 are disposed adjacent to distal end18 with end effector 20. Substrate 23 is relatively thin, and islaminated onto the elongate shaft body 14 without any protrusion or flapsuch that it does not catch on the trocar as the endoscopic instrument10 translates in or out of the trocar. Additionally, the substrate 23and sensing elements 18 are dimensioned to fit between the endoscopicinstrument 10 and trocar. Communication medium 26 may include, but isnot limited to, electrical traces, fiber optics, or any combinationthereof. In one exemplary implementation, one or more layers ofpolyimide with gold, silver, or copper electrical traces is used as orpart of the thin conformal substrate 23. Electronics module 28 comprisesat least an analog front end for interpreting sensor signals.Additionally, the electronics module 28 may contain, but is not limitedto, wired and/or wireless communication interface, power source, powercircuitry, battery, battery charging circuit, sensors, logic circuits,microprocessors, or any combination thereof. Additional sensors mayinclude, but are not limited to, accelerometers, gyroscopes, capacitivetouch, temperature, pressure, humidity, wireless antenna, magneticsensor, tilt sensor, or any combination thereof.

As shown in FIG. 2 , thin substrate 23 may also be flexible orsemi-flexible to match a flexible or semi-flexible endoscopic instrument20. In the case of flexible or semi-flexible instruments, thin substrate21 is preferably composed of materials 28 a that exceed the elasticlimit of the material or the effective elastic limit of the elongatedshaft body 14 of endoscopic instrument 10. The effective elastic limitis used where the geometry or assembly of the elongated shaft body 14allows it to exceed the elastic limit of its constituent materials suchas, but not limited to, hinges 28 b, springs 28 c, as shown in FIGS. 2 band 2 c , respectively, and spiral cut tubes (not shown). Substrate 23may also have its effective elastic limit increased to match theendoscopic instrument by modification in geometry such as, but notlimited to, folds 28 d or cuts 28 e in substrate 23, as shown in FIGS. 2d and 2 e , respectively.

In another exemplary implementation, as shown in FIGS. 3 a to 3 c ,substrate 31 includes built-in shielding to extraneous noise signals.Preferably the shielding comprises substrate material or lamination ableto minimize the effects of radiative, capacitive, inductive, magnetic,or conductive interference to sensor film 12. The shielding may beimplemented as the only noise filter, or in addition to shielding on thesensing elements 24, including circuitry associated therewith, andcommunication medium 26, or analog or digital filtering.

In one exemplary implementation, as shown in FIG. 3 a , elongated shaftbody 29 of endoscopic instrument 10 comprises longitudinal substratecore 31 with opposing surfaces carrying conductive material and soldermask coated thereon. Substrate core 31 with the masked conductivematerial is placed on elongated shaft body 29 and secured thereon byadhesive 30. In more detail, substrate core 31, such as polymide, or anysimilar material, is sandwiched between upper conductive layer 32 a andlower conductive layer 32 b. Upper conductive layer 32 a acts as agrounded shield, while bottom conductive layer 32 b relays sensorsignals from sensing elements 24 to electronics module 28. Upperconductive layer 32 a is insulated with a solder mask 33 a, while bottomconductive layer 32 b is insulated with a solder mask 33 b. Preferably,solder mask 33 a and solder mask 33 b are medical grade. In thisconfiguration the metal elongate shaft body 29 of endoscopic instrument10 acts as an additional shield. Additionally, an edge stitching 35 orsimilar, such as, but not limited to, edge metallization or conductivecoating, may be used to extend the shielded ground from upper conductivelayer 32 a around the edge of lower conductive layer 32 b which carriesthe sensed signals, which enhances the shielding protection. Theshielding protects the circuit from direct conducted noise and radiofrequency noise and also provides some protection to capacitivecoupling. Also, there is additional protection from inductive noise ifelongate shaft body 29 of endoscopic instrument 10 is composed of aferromagnetic material such as, but not limited to, martensitic orferritic grades of stainless steel.

In another exemplary implementation, as shown in FIG. 3 b , theupper-side of solder mask 33 a is replaced with a low friction,non-conductive material, such as a polymer, fluorinated ethylenepropylene (FEP), polyurethane, polytetrafluoroethylene (PTFE), orsimilar. The low friction, non-conductive material which is adhered toupper conductive layer 32 a as a layer via adhesive 30, around the sideof the other layers 31, 32 b, 33 b to the endoscopic instrument 10. Thelow friction, non-conductive material 36 reduces the sliding resistanceof the endoscopic instrument 10 as endoscopic instrument 10 travelswithin the trocar. In addition, the low friction, non-conductivematerial 36 improves wear resistance of endoscopic instrument 10,creates a higher resistance to conducted noise, and improves thedielectric strength.

In another exemplary implementation, as shown in FIG. 3 c , two layersof polyimide 31 a and 31 b and three layers of conductive material 32 a,32 b, and 32 c are included. Upper conductive layer 32 b conveying thesensor signals is sandwiched between polyimide layers 31 a, 31 b, whileouter layers of conductive material 32 a, 32 c are both grounded shieldswhich reduce capacitive coupling. In another exemplary implementation,looking at FIG. 3 d , extending from the previous implementation shownin FIG. 3 c , polyimide 31 comprises conductive layer 32 on one side anda sheet of grounded ferromagnetic metal 37 on the other side, instead oftop conductive layer 32 a of FIG. 3 c . Ferromagnetic metal 37 reducesinductive noise protection, and may include, but is not limited to,ferritic grades of stainless steel. If the metal of the elongate shaftbody 29 of endoscopic instrument 10 is also ferromagnetic, or if anothersheet is place underneath the signal layer 32 of conductive material,then the circuit is substantially protected from inductive noise.

In yet another exemplary implementation, the features in the previousexemplary implementations of FIGS. 3 b, 3 c and 3 d may be combined toaggregate the individual benefits. As an example shown in FIG. 3 e , lowfriction, non-conductive material outer layer 36, such as PTFE, may beplaced on top of ferromagnetic sheet 37 on top of double-sided polyimide28 in which top conductive layer 32 b relays the sensor signal and thebottom conductive layer 32 c is a grounded shield. If the endoscopicinstrument shaft 14 is ferromagnetic, then this provides substantialprotection against conductive, capacitive, inductive, and radiofrequency noise while improving wear resistance and sliding resistance.

As shown in FIG. 4 , sensor film 12 comprises substrate 40 with one ormore sensing elements 24 secured to elongate shaft body 42 of endoscopicinstrument 10. Generally, sensor film 12 is placed onto elongate shaftbody 42, and secured thereto by attachment means, such that sensingelements 24 measure the desired property. In one exemplaryimplementation one or more sensing elements 24 are electrically-based,and include electrical coupling 44 made by, but is not limited to,welding, conductive epoxy, conductive adhesive, spring contacts,crimping, mechanical interlocking, brushes, low temperature solder, orany combination thereof. In addition to functional contact, sensingelements 24 may also be mechanically coupled via mechanical couplingmeans 46 to protect the functional contacts of sensing elements 24and/or aid in the assembly thereof.

In one example, sensing elements 24 are implemented as metal orpiezoelectric strain gauges in order to measure forces. As such, straingauges 24 are configured to output a voltage signal based on a change inresistance when surgical instrument 10 to which they are attached toundergoes tension or compression. The one or more strain gauges 24 aremechanically coupled to the structural shaft 42 of the endoscopicinstrument 10. The coupling of the strain gauges 24 is preferablyaccomplished with as thin an adhesive 48 as possible, with a hardnessbetween that of the strain gauge 24 material and the shaft body 42material. Adhesive 48 may be, but is not limited to, cyanoacrylate,epoxy, or acrylic. Additionally, the one or more strain gauges 24 may bewelded to the structural shaft body 42 without or in addition toadhesive using, but not limited to, ultrasonic welding, solvent welding,melting, or some combination thereof. Also, the strain gauge 24 maycomprises more than one strain gauge pattern in each gauge. For example,in one exemplary implementation, a second strain gauge pattern is placedperpendicular to the first strain gauge pattern to provide thermalcompensation.

FIGS. 5 a to 5 e show different distal sensor types and configurationsin which endoscopic instrument 10 comprises one or more sensing elements54 on elongate shaft 50 and/or on end effector 52. Sensing elements 54include, but are not limited to, strain gauges, radio frequencyantennas, accelerometers, gyroscopes, magnetometers, piezoelectric,ultrasonic, capacitive, Braggs diffraction grating, thermometer, lightsensor, or any array, part of a larger system, hybrid, application of orcombination thereof such as, but not limited to, galvanic sensing,impedance spectroscopy, image sensing, photoplethysmogram (PPG), bloodflow, pulse transit time (PTT), ballistocardiogram (BCG),electromyography (EMG), electrocardiography (ECG or EKG),electroencephalogram (EEG).

In another exemplary implementation, one or more strain gauges 62 areplaced in a plurality of configurations, as shown in FIGS. 6 a to 6 c .For example, in FIG. 6 a , strain gauges 62 a, 62 b and 62 c are placedparallel to shaft 60 of instruments 10, and on opposite sides of shaft60. This configuration allows the differentiation of one direction ofbending and extension/compression which makes it useful for endoscopicinstruments 10 that are intended to operate in a single bendingdirection such as, but not limited to, retractors and endoscopicinstruments that are intended to operate in pure extension/compressionsuch as, but not limited to, biopsy tools and neurosurgical tools.

In another exemplary implementation, two strain gauges 63 a, 63 b areplaced parallel to shaft 60 of instrument 10 and equally spaced fromeach other, as shown in FIG. 6 b . The equal spacing of the straingauges 63 a, 63 b is preferred but other configurations are operable butwill not provide overall optimal resolution of the two bending momentsand compression and/or extension. This configuration allows thedifferentiation of both bending directions and extension/compressionwhich makes it useful in surgical instruments 10 such as, but notlimited to, graspers and needle drivers. In another exemplaryimplementation, as shown in FIG. 6 c , strain gauge 64 a with a patternaligned roughly at 45 degrees to the endoscopic instrument shaft 60 isused to determine the torque on endoscopic instrument shaft 60 withadditional strain gauge patterns 64 b, 64 c helping to determine bendingmoments, including compression and extension.

In situations where direct contact is required with the tissue, the oneor more sensing elements 62 a, 62 b, 62 c, 63 a, 63 b, 64 a, 64 b, and64 c may be, but are not limited to, being located beside, locatedthrough, or integrated into the end effector 66 or on the outside of thethin substrate 23 where the endoscopic instrument 10 may or may not bemodified to accommodate the one or more sensing elements 62 a, 62 b, 62c, 63 a, 63 b, 64 a, 64 b, and 64 c.

In another exemplary implementation, electrodes are placed on endoscopicinstrument shaft 60, integrated in end effector 66, or both. Theseelectrodes can be used for, but are not limited to, impedancespectroscopy, EMG, ECG, EEG, electrical stimulation, or any combinationthereof. In one application, a combination of two or more of impedancespectroscopy, EMG, and electrical stimulation can be used to assess andmonitor muscle viability.

As shown in FIG. 7 , in addition to sensing elements 70 placed at thedistal tip 72, one or more sensing elements 74 may be placed at any partof the mechanism which controls end effector 76 such as, but not limitedto, pull rods or cables. Preferably, sensing elements 74 are placed atlocations on endoscopic instrument 10 where no modification of theendoscopic instrument 10 is required.

In one exemplary implementation, one or more strain gauges at the distalportion of the endoscopic instrument 10 is augmented by anaccelerometer, gyroscope, tilt sensor, or any combination in order togive both position and force information. In another exemplaryimplementation where an energy storage device is used, any energystorage device that can be manufactured to a small size and high energydensity can be used and may include, but is not limited to, silveroxide, lithium, aluminum ion, zinc, thin film, supercapacitors, or anycombination thereof.

In another exemplary implementation, one or more temperature sensors inthe electronics module are used to compensate for thermal effects on thesensitive analog components. In another exemplary implementation, theelectronics can be selected to be able to withstand steam sterilizationknown as autoclaving by selecting electrical components that are ratedto exceed the typical temperature of autoclaving, which is 121° C., suchas, but not limited to, automotive rated components and lithiumpoly-carbon monofluoride batteries and by protecting the components fromdirect exposure to steam by, but not limiting to, plating, coating,potting, enclosing in a sealed case, or any combination thereof. As analternative to the previously mentioned implementation where steamsterilization known as autoclaving is used, the battery and/orelectronics can be made removable so that the removable parts do notneed to be selected to survive autoclaving.

In one exemplary implementation, sensor readings are relayed to thesurgeon to provide visual, tactile, or auditory feedback. In an instancewhere the feedback is visual, the information can be displayed by, butnot limited to, overlaying the information on an endoscope monitor,having a separate device to display the information, or having asoftware application to display the information on an existing devicesuch as, but not limited to, a phone, tablet, laptop, computer, ordisplay monitor.

FIG. 8 a shows a surgical feedback system which provides feedback to auser 80, such as a surgeon 80, or other medical professional, during asurgical operation on a body 81. Readings from sensors 82 associatedwith sensor film 84 conformally adhered to endoscopic instrument 86, arerelayed to electronics module 88 via at least one of an electrical,infrared, optical, or radio connection. In one exemplary implementation,electronics module 88 uses radio communication and is powered by a powersupply, such as a battery, such that there are no physical connectionsor line-of-sight issue constraining the movements of user 80 duringsurgery.

Electronics module 88 measures the sensor readings and transmits thedata to feedback device 90 where user 80 receives the feedback and canmodify their operation of the endoscopic instrument 86 accordingly. Inone exemplary implementation, electronics module 88 communicates thefeedback data, via radio transmission, to feedback device 90, such as amobile device comprising, but not limited to, a smartphone, tablet, orlaptop. The wireless communication to mobile device 90 allows medicaltrainees to quickly setup a feedback system and allows them to keep thegather data for later learning and analysis. Alternatively, electronicsmodule 88 communicates the feedback data via a wired or wirelessconnection to a display monitor 92.

In another exemplary implementation, as shown in FIG. 8 b , endoscopevideo imaging device 94 captures images pertaining to the surgicaloperation, and electronics module 88 communicates the sensed data, viaradio transmission, to video overlay unit 96, such that the sensorinformation is overlayed over the video images from endoscope video unit98, for display on monitor 92 in real time. This allows experiencedsurgeons 80 receive visual feedback from one or more sensors 82 on theirendoscopic instrument 86 through the monitor 92 which they would belooking at view the video images from endoscope video unit 98.

In another exemplary implementation, the sensorized instruments may, butare not required to, operate with other sensorized instruments orsensors. The sensorized instruments or sensors may or may not havedifferent sensors, sensor arrangements, number of sensors, orcombination thereof. These sensorized instruments and/or sensors may, ormay not, coordinate. Coordination can include, but is not limited to,sharing sensor data, synchronizing time, synchronizing events,requesting device operation changes, requesting data, requesting sensorreadings be taken, or any combination thereof. These sensorized devicesor sensors can be networked in any way or configuration. Networking caninclude, but is not limited to, planning instrument operation to notinterfere with one another such that coordination between the devices isminimized, coordinating between sensorized instruments or sensors,coordinating with a central hub, or any combination thereof.Accordingly, two endoscopic needle drivers are used with the sensor-filmcommunicates with strain gauges at the tips of the instruments. Thisconfiguration allows a complete assessment of the magnitude of theforces experienced in suture tying. These endoscopic needle drivers may,but are required to, have accelerometers and/or gyroscopes in theirelectronics modules in order to additionally capture the relative motionof suture tying.

In another exemplary implementation, one endoscopic instrument with asensor-film communicates with an optical system at the tip of theinstrument such as, but not limited to, PPG and an endoscope are used.The endoscope and sensorized instrument coordinate by momentarilyturning the light of the endoscope off so that the optical system canperform its reading in darkness. This momentary turning off ofendoscopic light can be done quickly enough such that the human eye doesnot notice and this can be done consistently to provide effectivelysimultaneous continuous reading in darkness and illumination forendoscopic viewing.

In another exemplary implementation, an endoscopic instrument with asensor-film communicates with an electrically-based sensor and anotherendoscopic instrument utilizing electrical or radio-frequency energysuch as, but not limited to, electrocautery, radio frequency ablation,or electrical stimulation are coordinated such that the electricalsensor is not reading and/or the electronics module is not connectedwhile the electrical or radio-frequency energy tool is in operation.This coordination helps to ensure accurate sensor reading and protectsthe electronics module from damage.

In another exemplary implementation, PPG or BCG is used as the sensorand is integrated with the end effector. Most importantly, this allowsthe surgeon to assess local blood oxygenation during surgery in additionto other metrics. This system can, but does not have to, be combinedwith another PPG, BCG, or ECG equipped endoscopic instrument or externalPPG, BCG, ECG, or other heart monitor to be used as part of PTT in orderto assess blood pressure during surgery and/or in real time.

In another exemplary implementation, up to four strain gauges are placedat the distal portion of the endoscopic instrument at different pointsand direction such that they can capture all forces and torquesexperienced by the tip of the instrument which consists of two bendingmoments, torque, and compression or extension. The mechanical couplingto the endoscopic instrument is accomplished by epoxy. These straingauges are then attached to a polyimide substrate with gold-platedcopper electrical traces by conductive adhesive. The thin substratefinally attaches to an electronics module which comprises an analogfront end, temperature sensor, Bluetooth transceiver, and battery. Thisallows the surgeon to see all of the forces experienced at the tip ofthe endoscopic instrument and record his motions in unison without anywires inhibiting the procedure. The readings from the temperature sensorare used to temperature compensate the readings from the analog frontend for additional accuracy. This exemplary implementation makes nomodification of the original endoscopic instrument and is completelywireless during surgery.

In another exemplary implementation in which the instrument undergoessteam sterilization known as autoclaving, the battery is a lithiumpoly-carbonmonofluoride battery, the components are all rated to above121° C., the electronics module is a sealed case, and the electronicscomponents are conformably coated, gold plated, and/or sealed. Thisallows the instrument to be sterilized without disassembling the deviceand prevents humidity-related inaccuracy and degradation of the analogfront end but still allows access to the electronics for calibration andeasy battery replacement.

In another exemplary implementation in which the endoscopic instrumenthas an end effector that requires one or more mechanical actuation rodsor cables, additional strain gauges may be placed on the exposedproximal section of the pull rods or cables. The one or more additionalstrain gauges can be used to capture actuation forces as well asdifferentiate pull rod or cable forces from compression/extension causedby external forces.

While these exemplary implementations are described in sufficient detailto enable those skilled in the art to practice the invention, it shouldbe understood that other exemplary implementations may be realized andthat logical and mechanical changes may be made without departing fromthe spirit and scope of the invention. The preceding detaileddescription is presented for purposes of illustration only and not oflimitation, and the scope of the invention is defined by the precedingdescription, and with respect to the attached claims.

The invention claimed is:
 1. A method for sensing at least one propertyassociated with an end effector of an instrument during a surgicalprocedure, wherein the instrument comprises an elongate shaft bodyhaving a proximal end and a distal end, and an end effector assembly atthe distal end operable by manipulation of an actuator mechanism at theproximal end; the method comprising the steps of: securing a sensor filmconformally to the elongate shaft body, the sensor film comprising: atleast one substrate core having a first surface and a second surface; atleast one sensing element; a first conductive layer residing on thefirst surface, the first conductive layer having a first solder maskcoated thereon, and wherein the first conductive layer is grounded; asecond conductive layer residing on the second surface, the secondconductive layer having a second solder mask coated thereon, and coupledto the at least one sensing element; causing the at least one sensingelement to measure at least one property and output a sensed signal andto convey the sensed signal via the second conductive layer to anelectronics module; and at the electronics module, receiving the sensedsignal and processing the sensed signal to determine the property. 2.The method of claim 1, wherein the instrument is used with a trocar. 3.The method of claim 1, wherein the electronic module processes thesensed signal and outputs feedback data to a user.
 4. The method ofclaim 3, wherein the feedback data comprises is at least one of visual,auditory, tactile, and any combination thereof.
 5. The method of claim3, wherein when the feedback data is visual, and information derivedfrom the feedback data is overlaid over a video on a display.
 6. Themethod of claim 5, wherein the video pertains to the surgical procedureassociated with the instrument.
 7. The method of claim 1, wherein the atleast one sensing element comprises at least one of a radio frequencyantenna, a force sensor, an accelerometer, a gyroscope, a magnetometer,a piezoelectric sensor, an ultrasonic sensor, a capacitive sensor, aBraggs diffraction grating, a thermometer, or any array thereof, or acombination thereof.
 8. The method of claim 1, wherein the first soldermask is a low friction, non-conductive layer, and the low friction,non-conductive layer adhered to a sheet of grounded ferromagnetic metalvia an adhesive and around edges of the at least one substrate core, anintermediate conductive layer, the second conductive layer and thesecond solder mask.
 9. The method of claim 1, wherein the at least onesensing element measures the at least one property and outputs thesensed signal.
 10. The method of claim 9, wherein the sensed signal istransmitted to the electronics module.
 11. The method of claim 1,wherein the at least one substrate core is semi-flexible.
 12. The methodof claim 1, wherein the at least one sensing element is placed on theend effector assembly associated with the instrument.
 13. The method ofclaim 1, wherein the at least one sensing element is placed on theactuator mechanism associated with the instrument.
 14. The method ofclaim 13, wherein the at least one sensing element is placed on pullrods and/or cables associated with the actuator mechanism.
 15. A methodfor sensing at least one property with an instrument, wherein theinstrument comprises an elongate shaft body; the method comprising thesteps of: securing a sensor film conformally to the elongate shaft body,the sensor film comprising: at least one substrate core having a firstsurface and a second surface; at least one sensing element; a firstconductive layer residing on the first surface, the first conductivelayer having a first solder mask coated thereon, and wherein the firstconductive layer is grounded; a second conductive layer residing on thesecond surface, the second conductive layer having a second solder maskcoated thereon, and coupled to the at least one sensing element; causingthe at least one sensing element to measure at least one property andoutput a sensed signal and to convey the sensed signal via the secondconductive layer to an electronics module.
 16. The method of claim 15,wherein the elongate shaft body comprises a proximal end and a distalend, and an end effector assembly at the distal end.
 17. The method ofclaim 16, wherein the end effector assembly is operable by manipulationof an actuator mechanism at the proximal end.
 18. The method of claim17, wherein the at least one sensing element is placed on the actuatormechanism.
 19. The method of claim 17, wherein the at least one sensingelement is placed on pull rods and/or cables associated with theactuator mechanism.
 20. The method of claim 15, wherein the electronicsmodule receives the sensed signal and processes the sensed signal.